When dispensing hydrogen to vehicles, a certain base infrastructure is required to safely and accurately deliver the product from a source of hydrogen stored at high pressure to the tank of the vehicle being fuelled. In general, this equipment includes tubing, valves to stop or meter the hydrogen flow, process measurement devices, mechanism for holding the fueling hose and removing water from the vehicle and an electrical panel that controls the system and acts as a user interface.
For every additional location or point where hydrogen is needed, an exact duplicate of the base infrastructure is required so two dispensing systems would require twice the base infrastructure. Additionally, whether refueling occurs indoors or outdoors would mandate a change to the system based on environment conditions.
In general, combining the functions of two dispensers into one filling point allows for multiple advantages including but not limited to the reduction of floor space for the equipment, reduction of capital equipment and the possibility to upgrade the system from one filling point to two filling points with little extra work required.
An additional concern with respect to a dispenser with one filling point is a hose that is external to the dispenser. This hose can be run over by the vehicle that is to be filled, can leak through fittings, create problems with tripping, damage through abrasion and injury if the hose breaks during use or even in the idle state.
Water can also be an issue as it can be present in the vehicle fuel tank and will need to be removed to ensure proper operation of the vehicles as well as avoiding corrosion in the fuel tank. The water removal process can be an issue when dispensers are located outdoors and freezing of the liquid in the hose and removal pumps can occur. Additionally, dispensers that are used outdoors need protection from the elements, insects, animal, temperatures and even sunlight.
Controlling the entire dispensing process is a programmable logic controller (PLC) located in an operator panel several feet away from the dispenser in an electrically non-hazardous area. The operator panel is the user interface to the system and contains the logic behind the dispensing process, maintains safe functionality and allows for the system to be started and stopped while logging data. Between these three devices, there are multiple conduits that contain electrical wires all add to system costs and installation time.
When two filling points are required, then double the equipment is required. This increases risk and problems with safety as now there is twice the number of potential leak points. Further there is twice the capital cost and a longer installation and commissioning time as well as increased maintenance costs due to the additional number of parts. The customer site also is affected as more space is used to with two dispensing ports. The dispensers themselves also have the limitation of having the fueling hose on only one side of the dispenser thereby limiting fueling to one side absent pulling the hose across the vehicle.
As such, there is a need for a dispenser that will overcome the difficulties presented by current dispenser setups and operation. The system of the invention will have less equipment and less leak points meaning that the system will be inherently safer. The use of less equipment for the same purposes will allow for a smaller footprint at the customer end user site. By using less equipment, there will be a corresponding decrease in the number of spare parts required. A single operator panel can be used to control both dispensing systems reducing costs and a single pump system can be employed at removing water from more than one vehicle.